Bulky fibrous element and process for making the same



D. F. MILLER 3,404,062

BULKY FIBROUS ELEMENT AND PROCESS FOR MAKING THE SAME Oct 1, 1968 4 Sheets-Sheet 1 Filed May 21, 1965 INVENTOR oo/vflw fZOYb M4117?) BY I 3,404,062 BULKY FIBROUs ELEMENT AND PROCESS FOR MAKING THE SAME Filed May 21, 1965 D. F. MILLER Oct. 1, 1968 4 Sheets-Sheet 2 m mm W MM W v, w F 7\ .0 o o o oo 4 0 o Q o0 .0 M o o o 00 00 000 1WW DVD L V QQ/NIVMQOOO WW M D U U Wm Wm QM OO O O O UDUU Wm NW N il .WW W NM U D b D U U m D Q a a; %M Q Ms. Q 19 mm N D U D D D b b Db mm @0 mm D D D D mm QNM 11 n I D. F. MILLER Oct. 1, 1968 BULKY FIBROUS ELEMENT AND PROCESS FOR MAKING THE SAME 4 Sheets-Sheet 5 Filed May 21, 1965 BULKY FIBROUS ELEMENT AND PROCESS FOR MAKING THE SAME.

Filed May 21, 1965' D- F. MILLER Oct. 1, 1968 4 Sheets-Sheet 4 INVENTOR DON/940 x-zoyo M1445? BY com United States Patent corporation of Delaware Filed May 21, 1965, Ser. No. 457,588 4 Claims. (Cl. 161-169) This invention relates to novel bulky fibrous elements of finite length having a variable fiber density from one end to the other and to a process for producing the novel bulky fibrous elements.

Crimped staple fibers are normally processed on a carding machine for orienting a substantial proportion of fibers in one direction. Cylinders containing card clothing, which is a series of wires (teeth) mounted on a supporting medium attached to the cylinder, normally pick up and align fibers so as to produce a carded web which is of relatively uniform fiber density throughout the width and continuous length of the web. This carded web is then condensed by conventional gathering methods into continuous card bulky fibrous elements, such as a sliver, which is also normally of relatively uniform volume and weight throughout the length of the sliver.

An object of this invention is to provide a novel bulky fibrous element of finite length having a fiber density which varies from one end of the element to the other. A further object is to provide a novel bulky fibrous element in which the fiber density decreases substantially uniformly from one end of the element to the other. Other objects will become apparent from the description hereinafter.

The objects of this invention are accomplished by providing a bulky fibrous element of finite length composed of crimped staple fibers having a total fiber weight in the range of from about 150 to about 1000 grains per yard which varies, in the direction of fiber orientation, from one end to the other. In the preferred embodiment, the fiber density varies uniformly from one end to the other with the high density end being in the range of from about 1.25 to about 2.0 times that of the low density end.

The novel process of this invention comprises, in general, transmitting a desired pattern of variable fiber density to a web section of finite length and then gathering the web section to form the bulky fibrous element. In the prefererd embodiment, the desired pattern is formed on a dofling cylinder as hereinafter described.

The term bulky fibrous element is meant to define configurations such as slivers which comprise a strand of loosely assembled fibers that is approximately uniform in cross-sectional area throughout its length (the cross-section being taken along a plane substantially perpendicular to the direction of fiber orientation) and without twist. The sliver may be formed by any suitable means, such as by cards, drawing and gill frames, combers, and the like. The outside geometry of the sliver or other bulky fibrous element may vary; e.g., it may be cylindrical (for rolled sliver), rectangular (for gathered sliver), or with cross-sections of round, square, rectangular, or other desired shapes. The fibers are oriented substantially in one direction, the direction being approximately that of the longitudinal dimension of the bulky fibrous element.

The embodiments of this invention and their advantages can be more readily understood by referring to the accompanying drawings.

FIGURE 1 is a perspective view of one means for producing the novel bulky fibrous elements of this invention,

FIGURES 2 through 7 are side elevation views of doffing rolls which can be utilized in the embodiment shown in FIGURE 1 to form the novel bulky fibrous elements of this invention,

FIGURES 8 and 9 are diagrammatic views illustrating alternative means to form the novel bulky fibrous elements of this invention, and

FIGURE 10 is a diagrammatic view illustrating one embodiment of the bulky fibrous elements of this invention.

With reference to FIGURE 1, there is shown one embodiment of means suitable for producing the novel bulky fibrous elements of this invention. From a source not shown, such as a feed apron and feed rolls, a loose web of staple fibers is deposited on main cylinder 10, which is mounted on shaft 12 and driven by means not shown. Stripper 14 and worker .16 are positioned adjacent main cylinder 10. Doffing roll 18 rotatably mounted on shaft 20 and driven by means not shown is aligned adjacent main cylinder 10 to remove the loose web of staple fibers from main cylinder 10. Dofiing roll 18 has continuous transverse areas 22 where no teeth are exposed. Similarly, between adjacent transverse areas 22 are triangular-shaped areas 24 which expose no teeth and which merge with areas 22. As shown, apex 26 of triangular-shaped area 24 touches one transverse area 22 and the base of the triangular-shaped area 24 then merges into the adjacent transverse area 22. Comb 30, which oscillates rapidly in a vertical direction, removes the patterned web 32 from dofiing roll 18, allowing it to be conveyed forward on web conveyor 34. Positioned above and somewhat transversely with respect to web conveyor 34 is sliver forming conveyor 36. As a web section 32 passes under sliver forming conveyor 36, a compressed fluid drives a longitudinal edge 38 of web section 32 upwardly against the bottom surface of sliver forming conveyor 36 which starts the web section rolling due to relative movement between web conveyor 34 and sliver forming conveyor 36.

Referring to FIGURES 2 through 7, there are shown alternative embodiments for the pattern of the areas exposing no teeth on the periphery of dofiing roll 18. In FIGURE 2, dofiing roll 18 has transverse area 22 positioned as desired around the circumference of doffing roll 18. Adjacent transverse areas 22 divide the dofling roll 18 into finite length L. Also within an area bounded by adjacent transverse areas 22, teeth are also removed or covered over in a series of small triangular-shaped areas 24. The apex 26 of triangular-shaped area 24 touches one of the transverse areas 22 and the base of the triangle merges into the adjacent transverse area 22. In FIGURE 3, the area bounded by adjacent transverse areas 22 has the teeth removed by a plurality of elliptical areas 40 which are staggered so that fibers are removed from the entire width of main cylinder 10. In FIGURE 4, the area bounded by adjacent transverse areas 22 has the teeth removed by a plurality of small triangular-shaped areas 50. In FIGURE 5, the teeth are removed so as to provide a plurality of small rectangular-shaped areas 60. In FIGURE 6, the teeth are removed so as to pr-ovide a plurality of small square-shaped areas 70. In FIGURE 7, the teeth are removed so as to provide a plurality of small circular-shaped areas 80.

In FIGURE 8 there is shown a diagrammatic view of one means for forming the novel bulky fibrous elements or slivers of this invention. Web 32 travels on web conveyor 34. Sliver forming conveyor 36 is positioned above and somewhat transversely with respect to web conveyor 34. A compressed air jet is positioned along one edge of web conveyor 34. The contour of the lower surface of sliver forming conveyor 36 is adjusted so that the clearance between web conveyor 34 and sliver forming conveyor 36 provides a controlled pressure as web 32 is being rolled (partially rolled sliver 42). The adjustment is accomplished by varying the position of backup rolls 92 which are rotatably mounted on arm 94 attached at fixed pivot 96 and regulated by screws 98 and 100'. Sliver chute 102 is positioned to forward the completely rolled sliver 44 away from web conveyor 34 to sliver conveyor 104. In FIGURE 9 there is shown a diagrammatic view of another means of forming the novel bulky fibrous elements or slivers of this invention. Web 32 travels on web conveyor 34. Sliver gathering conveyor 46 is positioned above and somewhat transversely with respect to web conveyor 34. Mounted on the belt surface of conveyor 46 are a row of pins 48. As the web section 32 comes into position on conveyor 34, these pins start to push or gather the Web across conveyor 34, forming folds or pleats similar to that shown with the partially gathered sliver 52. This gathering is continued across the full width of conveyor 34 to form the fully gathered sliver 54 which is discharged down sliver chute 102 to sliver conveyor 104.

As can be seen from FIGURES 8 and 10, the completely rolled sliver 44 has a substantially uniform crosssectional area throughout its length taken perpendicular to the direction of fiber orientation as indicated by arrow A. The fiber density varies from high density end 45 to low density end 47.

The operation of the apparatus illustrated in FIG- URES 1 and 8 is as follows. The loose web of staple fibers which are deposited on the main cylinder of the carding machine are carded by the worker and stripper. The carded web on the main cylinder is removed by the dofiing roll in the form of a plurality of web sections which are patterned and have a finite length. The periphery of the dofiing roll is normally covered with a series of fine teeth, pointed generally outward and slightly opposite the direction of rotation of the dofiing roll. These teeth pick up the fibers from the main cylinder, which turns many times faster than the dofling roll, and carry the web around to the point where the comb, oscillating rapidly in a vertical direction removes the web from the doffing roll and allows it to be conveyed forward. In the areas where the teeth are omitted from the doifing roll, the fibers do not adhere. So, by removing these teeth from lines or areas of the dofiing roll a pattern is produced which will then be transmitted to the web which is produced. The void areas are staggered so that the fibers are removed from the entire length of the main cylinder so that bands of fibers do not build up on the main cylinder. After the web having a variable fiber density is removed from the doffing roll by the comb, it is carried away by the web conveyor which is traveling at about the surface speed of the dofling roll or slightly faster. The web conveyor is supported from below as to provide a substantially flat surface. However, as the web passes under the sliver forming conveyor, air is emitted from a jet to blow a longitudinal edge of the web upwardly against the bottom surface of the sliver forming conveyor which starts the web section to roll upon itself due to the relative movement between the sliver forming conveyor and the web conveyor. The sliver forming conveyor slopes slightly upwardly in its direction of travel and the contour of its lower surface is adjusted so that clearance from the web conveyor provides controlled pressure as the web is rolling upon itself. After the web has been completely rolled, it is propelled by the sliver forming conveyor off the edge of the web conveyor to a sliver chute for feeding to other process equipment.

The pattern of the teeth removed on the doffing roll may be in the form of any suitable geometric shape. For example, triangles, circles, ellipses, squares, rectangles, S-shaped and C-shaped, may be advantageously used. In addition to having the patterns formed on the surface of the doffin-g roll by removing the teeth, films such as those made from polytetrafiuoroethylene and adhesive tapes could be adhered to and'rolled into the teeth of the card clothing to form the pattern. It is preferred to regulate the size of the patterns on the doffing roll surface, using a large number of small patterns in preference to a few large patterns. As the size of the pattern increases on the doffing roll, larger areas remain on the main cylinder in which the fibers have not been transferred to the doifing roll. As a result, the fibers will accumulate in areas on the main cylinder, and eventually the apparatus must be stopped to remove the fibers. It is also preferred to adjust the pattern so that the fiber density varies gradually from the beginning of one finite section on the doffing roll to the end of that same finite section. The preferred fiber density gradient is accomplished by adjusting the pattern areas so that the fiber density varies from about 1.25/1 to about 2.0/1 so that the novel bulky fibrous element or sliver of this invention has the same order of fiber density gradient from one end to the other. The fiber density, for most uses, will normally be in the range of from about 0.10 pound per cubic foot to about 1 pound per cubic foot.

Additionally, the web removed from the dofling roll may have a binder material present before being formed into the novel bulky fibrous element or sliver of this invention. Any suitable thermoplastic or thermosetting resinous or rubber binder composition may be applied to the carded web by known means. Suitable organicsoluble binders include natural rubber or synthetic elastomers (e.g., chloroprene, butadiene-styrene copolymers, butadiene-acrylonitrile copolymers), which may be used in the form of a latex dispersion or emulsion or in the form of a solution, vinyl acetate polymers and copolymers, acrylic polymers and copolymers such as those made from ethyl acrylate, methyl acrylate, butyl acrylate, methyl methacrylate, acrylic acid/acrylic and methacrylic ester copolymers, cellulose nitrate, cellulose acetate, cellulose triacetate, polyester resinsvsuch as ethylene terephthalate/ethylene isophthalate copolymers, polyurethanes such as the polymer from piperazine and ethylene bisohloroformate, polyamide polymers and copolymers, methoxymethyl polyamides, vinyl chloride polymers and copolymers such as vinyl chloride/vinylidene chloride copolymer latices. Alcohol soluble polyamide resins are also suitable organic-soluble binders. Suitable water-Soluble binders include materials such as polyvinyl alcohol, sodium alginate, acrylic acid polymers and copolymers such as polyacrylic acid, carboxymethyl cellulose, hydroxyethyl cellulose, dextrins, animal glue, soybean glue and sodium silicate. Suitable binders which are insoluble in organic solvents include polytetrafluoroethylene and ureaformaldehyde resin latices.

Additional suitable binder compositions include chlorosulfonated polyethylene; butyl rubbers, such as isobutylene/isoprene copolymers; polyhydrocarbons, such as polyethylene, polypropylene and the like and copolymers thereof; high molecular Weight polyethylene 'glycols sold unde rthe trade name of Polyox; epoxide resins, such as the diepoxide of bisphenol; polystyrene; alkyd resins, such as polyesters of glycerol with phthalic or maleic acid; polyester resins such as from propylene glycolmaleic an=hydride-styrene; phenol-formaldehyde resins; resorcinol-formaldehyde resins; polyvinyl acetals, such as polyvinyl butyral and polyvinyl formal; polyvinyl ethers, such as polyvinyl isobutyl ether; starch, zein, casein, gelatine, methyl cellulose, ethyl cellulose, polyvinyl fluoride, natural gums, polyisobutylene, shellac, terpene resins and rosin soaps. Segmented polymers, such as spandex polymers, polyether amides, polyether urethanes (e.g., those in US. Patent No. 2,929,800) and polyester/ urethanes are also suitable. A binder range of from about 4% to about 20% based on the total weight of the fibers is adequate for most purposes.

The binder composition may be applied to the fibers by means of dipping, spraying, and other known means provided the binder composition is used sparingly to attach fibers together at spaced contact points throughout the three dimensions of the web. In place of using resinous binders for attachment of fibers there may be used fiber solvents or partial solvents for point welding the fibers together, various heating means such as'ultra-high frequency for point welding the fibers together, as well as other known methods, for example, including a binder fiber of lower softening point than the structural fiber within the web material, and then heating the web to soften the binder fiber and attach the structural fibers together at a temperature above the softening point of the binder fiber, but below the softening point of the structural fiber.

A variety of different fibrous materials may be used in forming the carded web. Typical of the crimped staple fibers which may be employed are those made of polyamides, such as poly(hexamethylene adipamide), poly- (metaphenylene isophthalamide), poly(hexamethylene sebacamide), polybenzibidazole, polycaproamide, copolyamides and irradiation grafted polyamides, polyesters and copolyesters such as condensation products of ethylene glycol with terephthalic/isophthalic acids, ethylene glycol with a 98/2 mixture of terephthalic/S-(sodium sulfo)- isophthalic acids, and trans-p-hexahydroxylylene glycol with terephthalic acid, self-elongating ethylene terephthalate polymers, polyacrylonitrile, copolymers of acrylonitrile with other monomers such as vinyl acetate, vinyl chloride, methyl acrylate vinyl pyridine, sodium styrene sulfonate, terpolymers of acrylonitrile/methacrylate/sodium styrene sulfonate made in accordance with U.S. Patent No. 2,837,501, vinyl and vinylidene polymers and copolymers, polycarbonates, polyacetals, polyethers, polyurethanes such as segmented polymers described in U.S. Patents Nos. 2,957,852 and 2,929,804, polyesteramides, polysulfonamides, polyethylenes, polypropylenes, fluorinated and/or chlorinated ethylene polymers and copolymers (e.g., polytetrafluoroethylene, polytrifiuorochloro ethylene), certain 'cellulose derivatives, such as cellulose acetate, cellulose triacetate, regenerated cellulose, composite filaments such as, for example, a sheath of polyamide around a core of polyester as described in U.S. Patent No. 3,038,236 and self-crimped composite filaments, such as, two acrylonitrile polymers differing in ion: izable group content cospun side by side as described in U.S. Patent No. 3,038,237 and the like. Mixtures of blends of synthetic organic polymer fibers with natural fibers such as cotton, wool, mohair and the like may also be advantageously utilized for many applications. Blends of two or more synthetic organic fibers may likewise be utilized.

For a clearer understanding of the invention, the following specific example is given. This example is intended to be merely illustrative of the invention and not in limitation thereof. Unless otherwise indicated, all parts are by weight.

Example The dofiing roll on a standard carding machine, measuring 30 inches (76.2 cm.) in diameter and 60 inches (152.4 cm.) wide, was masked periodicall in a transverse direction and running along the entire width with continuous two-inch (5.08 cm.) wide strips of plastic backed adhesive tapes to provide finite sections of carded web. In addition, each area of the dofiing roll between the spaced transverse tapes was masked with a pattern of small circles cut from a standard plastic-backed adhesive tape, said circles being two inches (5.08 cm.) in diameter. The small tape circles were placed in a pattern, between the horizontal strips of tape on the roll so that each circle adhered to the wide tapes protraction from the dofiing roll. The pattern formed by the tape circles was one similar to the pattern of circles shown in FIGURE 7, such that there was a density gradient produced in the web coming off between each masked section of the dofiiing roll whereby the fiber density ratio of the card web from the end of the section containing the large number of circles on the cylinder to the end of the section containing the smaller number of circles on the cylinder was 1:1.55.

This same pattern of masking circles on the doffing roll was repeated in each section of the doffing roll between each two horizontal plastic tapes so that each card web section which was later removed from the dofiing roll contained the same fiber density gradient. The circular, taped pattern area covered 18.65% of the total web segment in each section of the dofl'ing roll. A blend of crimped staple fibers of polyethylene terephthalate polymer composed of 60 parts by weight of 4 denier per filament, 2-inch (5.08 cm.) long staple fibers having a threedimensional curvilinear crimp and 40 parts of 1.5 denier per filament, 1.5-inch (3.81 cm.) long staple fibers having a stutter-box type of crimp was fed to the carding machine and received on the dofiing roll in the form of a 60-inch (152.4 cm.) wide card web across the face of the dofiing r'oll. Each finite section of patterned card web was removed from the dofiing roll and transferred to a conveyor with the aid of 1) an air knife across the full width of the web to guide the web in transit through the air and help keep the web open, (2) an air foil in the form of a metal plate to help minimize currents around the periphery of the comb and keep the patterned web sections intact and (3) a reciprocating doffing comb positioned between the dofling roll and conveyor belt which reciprocates vertically to remove the finite sections of patterned card web from the cylinder and deposit them on the conveyor belt. The air knife consists of a tube running the full width of the web with small air outlets in the tube, with the air outlets directed downwardly toward webs being removed from the dofiing roll. The air knife also helps in limiting shrinkage of the section of card web as it is transported from doffing roll to conveyor. Each finite section of patterned card web was transporated from the dofiing roll to the conveyor belt. Each web section was then rolled into a sliver according to the arrangement illustrated in FIGURE 1. Each rolled sliver' was approximately 24 inches (61.0 cm.) long and 4 inches (11.6 cm.) in diameter, and the rolled sliver had a density gradient with a ratio of 121.55 from one end of the sliver to the other.

Although the novel bulky fibrous element or sliver of this invention has been described as being produced by forming a pattern on the surface of the doffing roll, the invention should not be SO restricted. Other methods may also be advantageously utilized. For example, a carded web of fibers could be produced on a standard worsted card and then by cutting the web in a zigzag pattern to form physically tapered web sections as it is being withdrawn from the card, the novel sliver would then be produced by a gathering step. Another suitable method is to differentially draw a standard sliver by passing it through a drafting system and varying the speed of the draw rolls so as to increase and decrease the amount of draw in a uniform and cyclic manner to produce a sliver which varies in weight from one end to the other. This product could then be chopped into finite lengths at the peak and troughs of density gradient to form the novel sliver of this invention. This process could be accomplished by modifying a conventional Servo Drafter by removing the automatic feed control on the drafter and reversing its operation so that when fed a uniform sliver rope, it would deliver a continuous sliver having the pulsating density.

The Web sections produced which have a physical taper or a pattern due to teeth removed from the doffing roll can be gathered together to produce the novel sliver of this invention by means other than rolling the novel sliver upon itself to form a rolled sliver. For example, several web sections could be either folded together or stacked and gathered by any conventional means to form the desired substantial-1y uniform cross-section in the plane taken substantially perpendicular to the direction of fiber orientation.

As an example, a novel sliver having a finite length of 15.5 inches (39.3 cm.) and an overall diameter of about 3.5 inches (8.9 cm.) can suitably have a gradient as shown in Table 1 below.

Table 1 Distance from high Weight,

weight end, inches grains/ yard 2 (5.1 cm.) 447 4 (10.2 cm.) 445 6 (15.3 cm.) 429 8 (20.3 cm.) 360 10 (25.4 cm.) 324 12 (30.5 cm.) 306 14 (35.6 cm.) 270 With respect to the pattern areas shown in FIGURES 4 through 7, Table 2 illustrates sample dimensions which have been found to be suitable.

Although it should be obvious that the finite length of the novel bulky fibrous element or sliver of this invention will vary with the use contemplated, lengths in the range of from about 12 inches (30.5 cm.) to about 24 inches (61.0 cm.) have been found suitable for most purposes.

This invention provides a novel bulky fibrous element or sliver of finite length which has a fiber density varying from one end to the other. This novel sliver can be utilized to eliminate variations in fiber density while producing a self-supporting fiber pack, by packing directionalized groups of fibers radial-1y around a central core and bonding these fibers together. To produce such selfsupporting fiber packs having substantially uniform fiber density throughout all dimensions of the fiber pack, it is only necessary to select and produce novel slivers in accordance with this invention which have a fiber density variation from one end to the other in the same ratio as the outside to the inside diameter of the fiber pack. The novel slivers of this invention may be utilized in the production of a wide variety of apparel and industrial textile material. For example, such textiles could be produced by packing a plurality of the novel slivers of this .8 invention which are aligned in the same direction and thereafter attaching them together to form a large porous block. The block can in turn be sliced perpendicular to or at an angle to the directionality of the fibers to form porous self-supporting sheets such as are described in US. Patent No. 3,085,922.

These porous self-supporting sheets are useful for making a wide variety of textile materials either as such or after having been glued to a backing material. Among the end uses are included cushioning materials, upholstery, carpets and other floor covering materials, tiles, blankets, fleeces, interlinings and outer wear, bedspreads, sweaters, uniforms and work clothes, rug pads, felts, glove and boot liners, slipcover backings, paint rollers, brushes, bath mats, pile linings, bathrobes, mens, womens and childrens sport clothing, and the like.

What is claimed is:

1. A bulky fibrous element of finite length and of substantially uniform cross-sectional area throughout its length composed of crimped untwisted staple fibers having a total fiber weight in the range of from about 150 grains to about 1000 grains per yard and a variable fiber density, said fibers being oriented substantially longitudinally of said element, and said fiber density varying in the direction of fiber orientation from one end of said bulky fibrous element to the other end, the high density end being in the range of from about 1.25 to about 2.0 times that of the low density end.

2. The bulky fibrous element of claim 1 wherein said fiber density varies uniformly from one end of said bulky fibrous element to the other end.

3. The bulky fibrous element of claim 1 wherein said high density end is in the range of from about 1.3 to about 1.6 times that of said low density end.

4. The process of making the bulky fibrous element of claim 1 utilizing a dofiing roll having a desired pattern thereon, comprising feeding a carded web of crimped staple fibers to said dofiing roll to produce a web of variable fiber density, removing the patterned web from said roll to a conveyor belt, and gathering the web section into said bulky fibrous element.

References Cited UNITED STATES PATENTS 8/1958 Jervis ROBERT F. BURNETT, Primary Examiner.

L. M. CARLIN, Assistant Examiner. 

1. A BULKY FIBROUS ELEMENT OF FINITE LENGTH AND OF SUBSTANTIALLY UNIFORM CROSS-SECTIONAL AREA THROUGHOUT ITS LENGTH COMPOSED OF CRIMPED UNTWISTED STAPLE FIBERS HAVING A TOTAL FIBER WEIGHT IN THE RANGE OF FROM ABOUT 150 GRAINS TO ABOUT 1000 GRAINS PER YEARD AND A VARIABLE FIBER DENSITY, SAID FIBERS BEING ORIENTED SUBSTANTIALLY LONGITUDINALLY OF SAID ELEMENT, AND SAID FIBER DENSITY VARYING IN THE DIRECTION OF FIBER ORIENTATION FROM ONE END OF SAID BULKY FIBROUS ELEMENT TO THE OTHER END, THE HIGH DENSITY END BE- 